WordNet sense 1 (any of various plants of various genera of the family Compositae having flowers that can be dried without loss of form or color):

everlasting flower

WordNet sense 2 (continuing forever or indefinitely):

ageless, eternal, perpetual, unceasing, unending, aeonian, eonian

WordNet sense 3 (continuing or enduring without marked change in status or condition or place):

lasting, permanent

WordNet sense 4 (without qualification; used informally as (often pejorative) intensifiers):

arrant, complete, consummate, gross, perfect, pure, stark, thoroughgoing, unadulterated, utter, double-dyed, sodding, staring, consummate, perfect

WordNet sense 5 (not diminished or moderated in intensity or severity; sometimes used as an intensifier):

unmitigated