WordNet sense 1 (a person related by blood or marriage):

relative

WordNet sense 2 (an act of narration):

telling, recounting

WordNet sense 3 ((law) the principle that an act done at a later time is deemed by law to have occurred at an earlier time):

relation back

WordNet sense 4 (the act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur):

coitus, congress, coition, congress, sexual intercourse, carnal knowledge, sex act, sexual congress, sexual relation