Adjective: obligatory u'bli-gu,to-ree [N. Amer], u'bli-gu-t(u-)ree [Brit]
- Morally or legally constraining or binding
"an obligatory contribution"; "attendance is obligatory";
- irremissible
- Required by obligation, compulsion or convention
"he made all the obligatory apologies"
See also: bounden [archaic], compulsory, de rigueur, imposed, incumbent on, indispensable, mandatory, necessary, prerequisite, required
Antonym: optional
Encyclopedia: Obligatory