heli-1

1.
variant of helio- before a vowel:
helianthus.

heli-2

1.
a combining form representing helicopter, in compound words:
helidrop; helilift; helitaxi.
Origin
by analysis of helicopter as heli- (an assumed combining form with -i-) + -copter; cf. copter
British Dictionary definitions for heli-

heli-

combining form
1.
helicopter: heliport
Word Origin
C20: shortened from helicopter

helio-

combining form
1.
indicating the sun: heliocentric, heliolithic
Word Origin
from Greek, from hēlios sun