Surest

adjective, surer, surest.
1.
free from doubt as to the reliability, character, action, etc., of something:
to be sure of one’s data.
2.
confident, as of something expected:
sure of success.
3.
convinced, fully persuaded, or positive:
to be sure of a person’s guilt.
4.
assured or certain beyond question:
a sure victory.
5.
worthy of confidence; reliable; stable:
a sure messenger.
6.
unfailing; never disappointing expectations:
a sure cure.
7.
unerring; never missing, slipping, etc.:
a sure aim.
8.
admitting of no doubt or question:
sure proof.
9.
destined; bound inevitably; certain:
sure death.
10.
Obsolete. secure; safe.
11.
be sure, to take care (to be or do as specified); be certain:
Be sure to close the windows.
adverb
12.
Informal. certainly; surely:
It sure is cold out. Sure, I’ll come.
Idioms
13.
for sure, as a certainty; surely:
It’s going to be a good day, for sure.
14.
make sure, to be or become absolutely certain:
I’m calling to make sure that you remember to come.
15.
sure enough, Informal. as might have been supposed; actually; certainly:
Sure enough, the picnic was rained out.
16.
to be sure,

without doubt; surely; certainly.
admittedly:
She sings well, to be sure, but she can’t act.

adjective
1.
(sometimes foll by of) free from hesitancy or uncertainty (with regard to a belief, conviction, etc): we are sure of the accuracy of the data, I am sure that he is lying
2.
(foll by of) having no doubt, as of the occurrence of a future state or event: sure of success
3.
always effective; unfailing: a sure remedy
4.
reliable in indication or accuracy: a sure criterion
5.
(of persons) worthy of trust or confidence: a sure friend
6.
not open to doubt: sure proof
7.
admitting of no vacillation or doubt: he is very sure in his beliefs
8.
bound to be or occur; inevitable: victory is sure
9.
(postpositive) bound inevitably (to be or do something); certain: she is sure to be there tonight
10.
physically secure or dependable: a sure footing
11.
(obsolete) free from exposure to harm or danger
12.
(usually imperative or dependent imperative; takes a clause as object or an infinitive, sometimes with to replaced by and) be sure, to be careful or certain: be sure and shut the door, I told him to be sure to shut the door
13.
for sure, without a doubt; surely
14.
make sure

(takes a clause as object) to make certain; ensure
(foll by of) to establish or confirm power or possession (over)

15.
(informal) sure enough, as might have been confidently expected; definitely: often used as a sentence substitute
16.
to be sure

without doubt; certainly
it has to be acknowledged; admittedly

adverb
17.
(sentence substitute) (informal) willingly; yes
18.
(sentence modifier) (informal, mainly US & Canadian) without question; certainly
supper