The bible never provides a dictionary either.
And the relatively small sample of word usage in the bible itself is insufficient to provide
meanings for many important words used.
hapax legomena for instance are words that appear ONLY ONCE.
http://www.jewishvirtuallibrary.org/jsource/judaica/ejud_0002_0008_0_08389.html
There are in biblical Hebrew about
1,300 hapax legomena (yet their precise number cannot be stated, since the exact definition is not clear as to whether or not they include homonymic hapax legomena). Most of them (about 900) are not too difficult to interpret, being derived from well-known biblical roots (as ʿ
emdah, Micah 1:11,
moʿ
omad, Ps. 69:3, both denoting "standing ground," being derived from the well-known root עמד, "to stand"). About 400, however, cannot be derived from known biblical roots and are therefore more difficult to interpret. Occurring only once, their exact meaning is more difficult to establish from context than that of words attested more often. Except for this fact and the possibility that hapax legomena may have arisen through error in transmission, the philological treatment of hapax legomena does not differ from that of words occurring more often. The meaning of both is elucidated by comparison with other Semitic languages, which often makes it possible to establish the etymology of the word treated.
That being said, there are probably over 200 words that no one knows the meaning of,
simply because the species of animals and birds and insects have changed over 4,000 years,
some becoming extinct and others migrating or having their habitats altered due to
climate change.
English translators have sometimes made guesses, and at other times substituted local species,
or given fanciful or legendary interpretations to difficult passages.
Thus there is a "unicorn" in the bible but not in Hebrew.
The "behemoth" is a mere transliteration, and 'leviathan' is unknown.
Even the
New Testament suffers from a remainder of words which occur only once,
or which have either obscure or multiple meanings that create translational or interpretational difficulties:
And of course the N.T. is only 1/4 the size of the Bible, so there is even less of a sample
to try to work out the meaning for certain words.
Here's a list of NT
hapax legomena generated from Logos 5, with a bit of manipulating in Excel. The document contains two lists, one in Scripture order, and one in alphabetical order. (There's also a version
for the Hebrew Bible.)