1) to draw back, let down, lower
1a) to withdraw: of a timid person
2) to withdraw one's self, i.e. to be timid, to cover, shrink
2a) of those who from timidity hesitate to avow what they believe
2b) to be unwilling to utter from fear
2c) to shrink from declaring, to conceal, dissemble
Part of Speech: verb
Citing in TDNT: 7:597, 1074
From G5259 and G4724; to withhold under (out of sight), that is, (reflexively) to cower or shrink, (figuratively) to conceal (reserve): - draw (keep) back, shun, withdraw.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ὑποστέλλω; click on the second column to search for that grammatical form of the root ὑποστέλλω; click on the third column to search for that word and grammatical form; click on the total to search for the root ὑποστέλλω.