The word "goddess"
No word for "goddess" exists in Biblical Hebrew.
Ashtoreth, the goddess of Sidon, is called "the god of Sidon" (אֱלֹהֵי צִדֹנִים) in I Kings 11:5. This is probably due to the fact that no female form of the word אֱלֹהִים 'elohim was in use, leading to the awkward designation of Ashtoreth as a "god." (Grammatically, the word אֱלֹהִים is plural, and the singular is אֱלוֹהַ 'eloah, which was also not used in a feminine form.) Apparently, no female word for "goddess" was in common use at the time of the writing of this passage.
The word b‘lt, which appears in the phrase m'hb‘lt in the Sinaitic Inscriptions to mean "goddess," also never appears in Biblical Hebrew. (This interpretation of the inscriptions is based on interpreting the b to represent the last letter of the first word as well as the first letter of the second word, making it m'hb b‘lt, "beloved of the goddess." Earlier translations translated hb ‘lt "bring sacrifices.")
The Sinaitic inscription has been identified (controversially) as an early form of Hebrew, and if this is true, it would show that Hebrew once had a word for goddess. However, Biblical Hebrew is not necessarily a direct descendant of whatever language is attested in these inscriptions.
Words other than "goddess" for a goddess
The concept of a goddess does appear in the Bible by different names. Ashtoreth was mentioned above. The אֲשֵׁרָה 'ashera tree (Deuteronomy 16:21) was apparently worshiped as a goddess, or at least used in the worship of a goddess (I Kings 15:13). An inscription mentions "YHVH of Samaria and his 'ashera." Some people concluded from this that YHVH was originally understood to have had a consort, but it could also be that the 'ashera was merely an object used in worship and not an actual goddess.
Interestingly, another tree, the 'ela (אֵלָה), which was used in worship (Hosea 4:13), could be understood to mean "goddess" (by analogy to אֵל 'el), and does mean "goddess" in modern Hebrew, but never has such a meaning in Biblical Hebrew.