Single
It is used as a single word. Compound adjectives with the -ed form are always hyphenated or spelled as one word. (Absent-minded is occasionally found as a single word without a hyphen.)
Generosity - Liberality in giving or willingness to give spare forebear (verb only) spare and part with (but not a single word)
A single word that can be defined as (or otherwise signifies)'too important to be done without' is 'necessary.' When and where something is 'too important to be done without,' that same something is 'necessary.'
cleverness
My family has a interest in sports.
Perfunctory
Silent.
Aloof
holistic
atheist
Single
Sure! Run, jump, eat, sleep, read, write, and swim are examples of single-word verbs.
She is currently enjoying the single life after ending a long-term relationship.
"Altruism" is a word that describes the act of giving without expecting anything in return. It emphasizes selflessness and compassion towards others.
The verb, astonish, might do.
Volunteer.