before vowels hapl-, word-forming element meaning "simple, single; simply, once," from Greek haploos, haplous "single, simple" (as opposed to "compound"); "natural, plain," from PIE compound *sm-plo-, from root *sem- (1) "one; as one, together with" + *-plo- "-fold" (from PIE root *pel- (2) "to fold"). Compare simple, which represents the same compound in Latin.

word-forming element meaning "sun," from Greek hēlios "sun" (from PIE root *sawel- "the sun").

word-forming element meaning "half," from Latin hemi- and directly from Greek hēmi- "half," from PIE root *semi-, which is the source of Sanskrit sami, Latin semi- (see semi-), Old High German sami- "half," and Old English sam-, denoting a partial or imperfect condition (see sandblind).