/ Dictionary / Index H helical: Meaning and Definition of Find definitions for: hel•i•cal Pronunciation: (hel'i-kul, hē'li-), [key] — adj. pertaining to or having the form of a helix; spiral. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: helical (Thesaurus) helic- helical gear Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language