certain meaning
EN
[ˈsɜːtn̩] [ˈsɝtn̩] [ˈsɝtən] [-ɜː(ɹ)tən] 
CA US WCertain
FR certain 
- AdjectiveCOMmore certainSUPmost certainSUF-ain
- Sure, positive, not doubting.
- I was certain of my decision.
- OBS Determined; resolved.
- Not to be doubted or denied; established as a fact.
- Actually existing; sure to happen; inevitable.
- Bankruptcy is the certain outcome of your constant gambling and lending.
- Unfailing; infallible.
- Fixed or stated; regular; determinate.
- Not specifically named; indeterminate; indefinite; one or some; sometimes used independently as a noun, and meaning certain persons; see also "one".
- Sure, positive, not doubting.
- Determiner
- Having been determined but unspecified. The quality of some particular subject or object which is known by the speaker to have been specifically singled out among similar entities of its class.
- Having been determined but unspecified. The quality of some particular subject or object which is known by the speaker to have been specifically singled out among similar entities of its class.
- More Examples
- Used in the Middle of Sentence
- A certain amount of collateral damage and destruction to the surrounding environment has always been viewed as a necessary but generally undesirable by-product of military conflict.
- I am quite sure that too much bed, if not too much sleep, is prejudicial, though a certain amount is absolutely necessary.
- Having a husband who was so brimmingly full of fun might have involved a certain strain; still, the fact that Véra was not similarly blessed is just a reminder of the planetary norm.
- Used in the Beginning of Sentence
- Certain minerals may exsolve into the atmosphere from an erupting volcano.
- Certain wagering individuals would profit from the outcome. ( adjectival )
- Certain plants, viperine snake venom, resin and various bacteria contain toxalbumins
- Used in the Middle of Sentence
Definition of certain in English Dictionary
- Part-of-Speech Hierarchy
- Adjectives
- Determiners
- Adjectives
Source: Wiktionary
Grammatically, this word "certain" is an adjective. It's also a determiner.