gap-toothed (adj.) Look up gap-toothed at Dictionary.com
"having teeth set wide apart," 1570s, from gap (n.) + toothed "having teeth" (of a certain kind); see tooth (n.). Chaucer's gat-toothed, sometimes altered to this, is from Middle English gat (n.) "opening, passage," from Old Norse gat, cognate with gate (n.).