medieval French silver coin corresponding to the English penny, early 15c., from Old French dener, a small coin of slight value, roughly equivalent to the English penny, in use in France from the time of Charlemagne to early modern times, from Latin denarium, from denarius, name of a Roman coin (source also of Spanish dinero); see denarius.

"one who denies," c. 1400, agent noun from deny (v.).

Proto-Indo-European root meaning "ten."

It forms all or part of: cent; centenarian; centenary; centi-; centime; centurion; century; centennial; cinquecento; dean; deca-; decade; decagon; Decalogue; Decameron; decapod; decathlon; December; decennial; deci-; decile; decimal; decimate; decimation; decuple; decussate; denarius; denier (n.) "French coin;" dicker; dime; dinar; doyen; dozen; duodecimal; duodecimo; eighteen; fifteen; fourteen; hecatomb; hendeca-; hundred; icosahedron; nineteen; nonagenarian; octogenarian; Pentecost; percent; quattrocento; Septuagint; sexagenarian; seventeen; sixteen; ten; tenth; thirteen; thousand; tithe; -ty (1).

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dasa, Avestan dasa, Armenian tasn, Greek deka, Latin decem (source of Spanish diez, French dix), Old Church Slavonic deseti, Lithuanian dešimt, Old Irish deich, Breton dek, Welsh deg, Albanian djetu, Old English ten, Old High German zehan, Gothic taihun "ten."

"act of denying one's own wishes; refusal to satisfy one's own desires," 1640s, from self- + denial.

Self-denial is to be presumed wise, necessary, or benevolent, unless indication is given to the contrary ; it may be the denial of selfishness; it may be not only the refusal to take what one might have, but the voluntary surrender of what one has ; it may be an act, a habit, or a principle. [Century Dictionary]

Related: Self-denier; self-denying (adj.) is by 1630s as "involving self-denial," also "characterized by or involving denial of one's self."