I. ˈekˌsän noun
( -s )
Etymology: modification of French exempt subordinate in the cavalry commanding in the absence of the higher company officers — more at exempt
: one of four officers of the yeomen of the British royal guard ranking below ensign who in turn act as resident commanders in the absence of superior officers — called also exempt
II. ˈekˌsän noun
( -s )
Etymology: ex- (I) + -on (II)
: a polynucleotide sequence in a nucleic acid that codes information for protein synthesis and that is copied and spliced together with other such sequences to form messenger RNA — compare intron herein
• ex·on·ic ekˈsänik adjective