Boyd’s Bible Dictionary:
The unknown wood of Noah’s ark
(Gen. 6:14).
Concise Bible Dictionary:
The wood with which Noah built the Ark. For so large a vessel it must have been a strong wood, but “gopher” is the Hebrew word and it is not known to what it refers (Gen. 6:14).
Strong’s Dictionary of Hebrew Words:
Meaning:
from an unused root, probably meaning to house in; a kind of tree or wood (as used for building), apparently the cypress
Jackson’s Dictionary of Scripture Proper Names:
coverer: pitch-wood