Nemesis

an opponent that cannot be beaten or overcome

Nettle

to irritate; vex

Nocturnal

of or occurring at night

Nullify

to make useless; cancel; undo

Nurture

to nourish, to feed; to educate; to train; to foster

Obese

extremely fat; grossly overweight

Obtrude

to impose oneself or one’s ideas on others; to stick out

Offal

waste parts, especially of a butchered animal; rubbish

Officious

interfering; intrusive; eager in offering
unwanted services or advice

Onerous

troublesome or oppressive; burdensome