Essential; crucial; extremely important.
Having semantics that incorporates mutable variables.
Expressing a command; authoritatively or absolutely directive.
Of, or relating to the imperative mood.
A verb in imperative mood.
The grammatical mood expressing an order (see jussive). In English, the imperative form of a verb is the same as that of the bare infinitive.
An essential action, a must: something which is imperative.
Very important.
Invigorating or life-giving.
Containing life; living.
Necessary to continued existence.
Necessary to the continuation of life; being the seat of life; being that on which life depends.
Capable of living; in a state to live; viable.
Relating to the recording of life events.
Relating to, or characteristic of life.