decumbiture
n. the act of going to bed when sick

leighster
n. a female liar

agerasia
n. youthful appearance in an old person

Also:

neanimorphism
n. the quality of looking younger than one’s age

psaphonic
n. planning one’s rise to wealth and fame

exsibilation
n. the action of hissing off the stage

opsimath
n. one who studies late in life

phobophobia
n. fear of phobias

eccedentesiast
n. one who fakes a smile

adoxography
n. fine writing on a trivial subject

fysigunkus
n. one who lacks curiosity