Sexual attraction, preferentially, to teenagers who have been through puberty. It does not mean preference for adults, as some have thought. The age range is generally considered to be 15-19. It should be noted that almost all adults profess attraction to this age group, and that one is classified as an ephebophile only if this age group is chosen preferentially.
The beloved may or may not have reached the age of consent, depending on local laws.
Watch out, man! People will call you a pedo!
I'm no pedo! I like them grown up, just young. I'm have ephebophilia.
(From the Greek "epi-", upon + "Hebe", the goddess of youth, signifying those who have completed puberty + "-philia", loving.)