1. (noun) required activity

• demand

2. (noun) anything indispensable

• essential
• necessary
• necessity
• requisite

3. (noun) something that is required in advance

• prerequisite

1. (noun) anything indispensable

• desideratum
• must
• need
• want

2. (noun) something that is required in advance

• academic requirement
• essential condition
• sine qua non
• precondition

1. (noun) required activity

• duty
• obligation
• responsibility

2. (noun) anything indispensable

• thing

3. (noun) something that is required in advance

• duty
• obligation
• responsibility

1. (noun) required activity

• ask
• expect
• require
• ask
• ask
• call for
• call for
• demand
• demand
• involve
• involve
• necessitate
• necessitate
• need
• need
• postulate
• postulate
• require
• require
• take
• take

2. (noun) anything indispensable

• ask
• call for
• demand
• involve
• necessitate
• need
• postulate
• require
• take
• destitute
• impoverished
• indigent
• necessitous
• needy
• poverty-stricken
• essential
• indispensable
• necessary
• need
• require
• want
• needed
• needful
• required
• requisite

3. (noun) something that is required in advance

• prerequisite

1. (noun) anything indispensable

• inessential
• nonessential