There are 15 words that start with 'allel'.
| allele | alleles |
| allelic | allelism |
| alleluia | allelisms |
| alleluias | allelomorph |
| allelopathy | allelomorphs |
| allelopathic | allelomorphic |
| allelopathies | allelomorphism |
| allelomorphisms | |
Note: These 15 words that start with 'allel' are found from the USA & Canada version of the tournament Scrabble word list.