permanent
adjective [not gradable] 
lasting for a long time or forever 
She is looking for a permanent place to stay.
Are you looking for a temporary or a permanent job?
The disease can cause permanent damage to the brain.
Every year in Britain, 30 000 people suffer permanent disabilities as a result of strokes.
A semi-permanent hair dye will wash out after about three months.
His work is on permanent display in the gallery.
He entered the United States in 1988 as a permanent resident because of his marriage to a U.S. citizen.
She is an Indian citizen with British permanent-resident status.

Permanent can also be used to mean that something exists or happens all the time. 
Mont Blanc has a permanent snow cap.
Our office is in a permanent state of chaos.

Permanent is also Am for perm. 

(British) A permanent secretary is a government official who belongs to the Civil Service the official departments responsible for putting government plans into action rather than an elected government. 
He was the permanent secretary at the Department of Health.

Permanent wave is formal for perm. 

permanently
adverb [not gradable] 
Smoking is likely to damage your health permanently (=forever).
He and his family have settled permanently (=forever) in the States.
All three countries seem to be permanently (=always) on the brink of war with each other.
I seem to be permanently broke (=I never have any money).

permanence, formal permanency
noun [U] 
Permanence means staying the same or continuing for a long time. 
A loving family environment gives children that sense of stability and permanence which they need.