keep in one's mind; "I cannot retain so much information"
secure and keep for possible future use or application; "The landlord retained the security deposit"; "I reserve the right to disagree"
allow to remain in a place or position; "We cannot continue several servants any longer"; "She retains a lawyer"; "The family's fortune waned and they could not keep their household staff"; "Our grant has run out and we cannot keep you on"; "We kept the work going as long as we could"
hold within; "This soil retains water"; "I retain this drug for a long time"
not easily perturbed or excited or upset; marked by extreme calm and composure; "hitherto imperturbable, he now showed signs of alarm"; "an imperturbable self-possession"; "unflappable in a crisis"