adjective.
Helpless at birth (of young animals); or having young which are helpless at birth.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
(of hatchlings) naked and blind and dependent on parents for food
Word Usage
"After all, we are big-brained altricial mammals, born helpless and requiring extensive adult care, who learn a variety of skills through different sorts of play."