ectomorph

As a letter s

is the letter s with a.

As a noun ectomorph is

someone with a lean, only slightly muscular body.

As nouns the difference between ectomorph and null

is that ectomorph is someone with a lean, only slightly muscular body while null is zero, nil; the cardinal number before einn.

is likely misspelled.

has no English definition.

As a noun ectomorph

is someone with a lean, only slightly muscular body.

As nouns the difference between ecomorph and ectomorph

is that ecomorph is a local variety of a species whose appearance is determined by its ecological environment while ectomorph is someone with a lean, only slightly muscular body.