Definitions:

1. (of persons) worthy of trust or confidence adjective
   • a sure (or trusted) friend
2. certain not to fail adjective
   • a sure hand on the throttle
3. definitely or positively (`sure' is sometimes used informally for `surely') adverb
   • the results are surely encouraging
4. having or feeling no doubt or uncertainty adjective
   • confident and assured
5. impossible to doubt or dispute adjective
   • indisputable (or sure) proof
6. infallible or unfailing adjective
   • a sure (or true) sign of one's commitment
7. physically secure or dependable adjective
   • a sure footing

Synonyms:

• certain
• indisputable
• surely
• trusted

NearBy Words:

• sure-enough
• sure-fire
• sure-footed
• sure-handed
• surefooted
• surely
• sureness
• surety