1. (noun) someone devoted to the promotion of human welfare and to social reforms

• do-gooder
• humanitarian

2. (noun) a component that is added to something to improve it

• add-on
• addition

1. (noun) a component that is added to something to improve it

• additive
• afterthought
• annex
• annexe
• extension
• wing
• attachment
• elongation
• extension

1. (noun) someone devoted to the promotion of human welfare and to social reforms

• benefactor
• helper

2. (noun) a component that is added to something to improve it

• component
• constituent
• element

1. (noun) someone devoted to the promotion of human welfare and to social reforms

• ameliorate
• amend
• better
• improve
• meliorate
• benefit
• do good

2. (noun) a component that is added to something to improve it

• add
• bestow
• bring
• contribute
• impart
• lend
• add on
• ameliorate
• amend
• better
• improve
• meliorate