#1 keep back v. keep under control; keep in check; "suppress a smile"; "Keep your temper"; "keep your cool". wn
#2 keep back v. secure and keep for possible future use or application; "The landlord retained the security deposit"; "I reserve the right to disagree". wn
#3 keep back v. hold back; refuse to hand over or share; "The father is withholding the allowance until the son cleans his room". wn
vizzz