This species is distinguished by the following set of characters: naked cheek and breast; fully scaled dorsolateral body surface; anteroventral profile of lower jaw somewhat strongly concave; upper oral valve with sparse minute, slender papillary projections; bicuspid preorbital spine, not expanded distally; second dorsal and anal fin spines elongated,

almost reaching to the base of fifth dorsal fin soft ray and extending beyond the base of fifth anal fin soft ray when fins are appressed; a distinct yellow semicircular marking just behind pectoral fin base, larger than pupil and smaller than eye in size; usually almost straight dark vertical lines (not wavy) dorsolaterally on the body in preserved specimens (Ref. 74926).

Similar to Nuchequula gerroides and N. longicornis in overall body appearance, naked cheek and breast, and scaled anterior dorsolateral surface of body; however, N. flavaxilla is different from the latter two species by the preorbital spine not expanded distally (vs. expanded distally in the latter two species) (Ref. 74926).