The Collaborative International Dictionary of English v.0.48:

Procreation \Pro`cre*a"tion\, n. [F. procr['e]ation, L,
   procreatio.]
   The act of begetting; generation and production of young.
   --South.
   [1913 Webster]

WordNet (r) 3.0 (2006):

procreation
    n 1: the sexual activity of conceiving and bearing offspring
         [syn: reproduction, procreation, breeding, facts of
         life]

Moby Thesaurus II by Grady Ward, 1.0:

93 Moby Thesaurus words for "procreation":
   abiogenesis, act of love, adultery, aphrodisia, archigenesis, ass,
   balling, begetting, biogenesis, birth, blastogenesis, breeding,
   budding, burgeoning, carnal knowledge, climax, cohabitation,
   coition, coitus, coitus interruptus, commerce, congress,
   connection, copula, copulation, coupling, crossbreeding,
   development, diddling, digenesis, dissogeny, endogamy,
   engenderment, epigenesis, eumerogenesis, excrescence, fornication,
   gemmation, generation, genesis, germination, growth, heterogenesis,
   histogenesis, homogenesis, inbreeding, intercourse, intimacy,
   isogenesis, linebreeding, lovemaking, making it with,
   marital relations, marriage act, mating, maturation, meat,
   merogenesis, metagenesis, monogenesis, multiplication, onanism,
   orgasm, orthogenesis, outbreeding, outgrowth, overgrowth, ovum,
   pangenesis, pareunia, parthenogenesis, proliferation, propagation,
   pullulation, relations, reproduction, screwing, sex, sex act,
   sexual climax, sexual commerce, sexual congress,
   sexual intercourse, sexual relations, sexual union, sleeping with,
   sperm, spontaneous generation, sprouting, upgrowth, vegetation,
   venery, xenogamy



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PROCREATION. The generation of children; it is an act authorized by the law
of nature: one of the principal ends of marriage is the procreation of
children. Inst. tit. 2, in pr.