Boyd’s Bible Dictionary:
(glide). An unclean bird of prey (Deut. 14:13). The European kite; but vulture (Lev. 11:14).
Concise Bible Dictionary:
One of the unclean birds (Deut. 14:13). In the parallel passage in Leviticus 11:14 the word is omitted, as it is by the LXX, the Samaritan, and four Hebrew MSS. What bird is referred to is unknown.