As a known and sure fact, we are unsure for there exists several interpretations in this matter. We are not even sure that in is of Hebrew origin. It may in fact be of Egyptian origin. Apparently there are nearly seventy (70) ways to interpretation the name of Mary.
To make a definitive interpretation seems almost unrealistic at the present moment in time.
It is antecedently probable that God should have chosen for Mary a name suitable to her high dignity. What has been said about the form of the name Mary shows that for its meaning we must investigate the meaning of the Hebrew form miryam. Bardenhewer has published a most satisfactory monograph on the subject, in which he explains and discusses about seventy different meanings of the name miryam (Der Name Maria. Geschichte der Deutung desselben. Freiburg, 1895)... Fr. von Hummelauer (in Exod. et Levit., Paris, 1897, p. 161) mentions the possibility that miryam may be of Egyptian origin.
Most interpreters derive the name Mary from the Hebrew, considering it either as a compound word or as a simple. Miryam has been regarded as composed as a noun and a pronominal suffix, or of a noun and an adjective, or again of two nouns. Gesenius was the first to consider miryam as a compound of the noun meri and the pronominal suffix am; this word actually occurs in II Esd., ix, 17, meaning "their rebellion". But such an expression is not a suitable name for a young girl. Gesenius himself abandoned this explanation, but it was adopted by some of his followers.
Here a word has to be added concerning the explanation Stella maris, star of the sea. It is more popular than any other interpretation of the name Mary, and is dated back to St. Jerome (De nomin. hebraic., de Exod., de Matth., P.L., XXIII, col, 789, 842). But the great Doctor of the Church knew Hebrew too well to translate the first syllable of the name miryam by star; in Isaiah 40:15, he renders the word mar by stilla (drop), not stella (star). A Bamberg manuscript dating from the end of the ninth century reads stilla maris instead of stella maris. Since Varro, Quintillian, and Aulus Gelliius testify that the Latin peasantry often substituted an e for an i, reading vea for via, vella for villa, speca for spica, etc., the substitution of maris stella for maris stilla is easily explained. Neither an appeal to the Egyptian Minur-juma (cf. Zeitschr. f. kathol. Theol., IV, 1880, p. 389) nor the suggestion that St. Jerome may have regarded miryam as a contracted form of me'or yam (cf. Schegg, Jacobus der Bruder des Herrn, Munchen, 1882, p. 56 Anm.) will account for his supposed interpretation Stella maris (star of the sea) instead of stilla maris (a drop of the sea).
It was Hiller (Onomasticum sacrum, Tübingen, 1706, pp. 170, 173, 876) who first gave a philological explanation of miryam as a simple word. The termination am is according to this writer a mere formative affix intensifying or amplifying the meaning of the noun. But practically miryam had been considered as a simple noun long before Hiller. Philo (De somn., II, 20; ed. Mangey, II, 677) is said to have explained the word as meaning elpis (hope), deriving the word either from ra'ah (to see, to expect?) or from morash (hope); but as Philo can hardly have seriously believed in such a hazardous derivation, he probably presented Mary the sister of Moses as a mere symbol of hope without maintaining that her very name meant hope. In Rabbinic literature miryam is explained as meaning merum (bitterness; cf. J. Levy, Neuhebraisches und chaldaisches Wörterbuch uber die Talmudim und Midraschim, Leipzig, 1876-89, s.v. merum); but such a meaning of the word is historically improbable, and the derivation of miryam from marar grammatically inadmissible. Other meanings assigned to miryam viewed as a simple word are: bitter one, great sorrow (from marar or marah; cf. Simonis, Onomasticum Veteris Testamenti, Halae Magdeburgicae, 1741, p. 360; Onom. Novi Test., ibid., 1762, p. 106); rebellion (from meri; cf. Gesenius, Thesaur. philol. critic. ling. hebr. et chald. Beter. Testamenti, edit. altera, Lipsiae, 1835-38, II, p. 819b); healed one (cf. Schäfer, Die Gottesmutter in der hl. Schrift, Münster, 1887, pp. 135-144); fat one, well nourished one (from mara; cf. Schegg, Evangelium nach Matthäus, Bd. I, München, 1856, p. 419; id., Jacobus der Bruder des Herrn, München, 1882, p. 56; Furst, Hebr. und chald. Hanwörterb. über d. alte Test., Leipzig, 1857-1861, s.v. miryam); mistress (from mari; cf. v. Haneberg, Geschichte d. biblisch. Offenbarung, 4th edit., Regensburg, 1876, p. 604); strong one, ruling one (from marah; cf. Bisping, Erklärung d. Evang. nach Matth., Münster, 1867, p. 42); gracious or charming one (from ra'am which word does not have this meaning in the Old Testament; cf. v. Haneberg, 1, c.); myrrh (from mor, though it does not appear how this word can be identified with miryam; cf. Knabenbauer, Evang. sec. Matth., pars prior, Parisiis, 1892, p. 44); exalted one (from rum; cf. Caninius, De locis S. Scripturae hebraicis comment., Antverpiae, 1600, pp. 63-64).
In 1906 Zorrell advanced another explanation of the name Mary, based on its derivation from the Egyptian mer or mar, to love, and the Hebrew Divine name Yam or Yahweh (Zeitschrift für katholische Theologie, 1906, pp. 356 sqq.). Thus explained the name denotes "one loving Yahweh" or "one beloved by Yahweh". We have already pointed out the difficulty implied in an Egyptian origin of the name Mary. Probably it is safer to adhere to Bardenhewer's conclusions (l. c., pp. 154 sq.): Mariam and Maria are the later forms of the Hebrew miryam; miryam is not a compound word consisting of two nouns, or a noun and an adjective, or a noun and a pronominal suffix, but it is a simple though derivative noun; the noun is not formed by means of a prefix (m), but by the addition of a suffix (am). Presupposing these principles, the name miryam may be derived either from marah, to be rebellious, or from mara, to be well nourished. Etymology does not decide which of these derivations is to be preferred; but it is hardly probable that the name of a young girl should be connected with the idea of rebellion, while Orientals consider the idea of being well nourished as synonymous with beauty and bodily perfection, so that they would be apt to give their daughters a name derived from mara Mary means therefore The beautiful or The perfect one. - The Name of Mary
Yona Sabar a professor of Hebrew and Aramaic in the department of Near Eastern Languages & Cultures at UCLA adds this to the subject: