Yes - concern.
Some seven letter words ending in N are:BritainbullioncautioncurtaindrunkendungeonemotionenvironerosionfashionfissiongelatinLincolnkitchenmansionmentionmillionmissionovationpassionpelicanportionpuritanvenisonversion
nonagon
Niagara
certain
Inhuman
wearson
an on in are all 2 letter words ending in N.
inflection
alodium
conflagration
damn
German