As a verb nidder
is to keep down or under.
As a noun ridder is
one who, or that which, rids.
nidder
English
Verb
(
en verb)
To keep down or under.
To press hard upon; straiten (applied to bounds).
To pinch or starve with cold or hunger; stunt in growth.
To harass; grill; plague; annoy. 
