Find complete word in text using Regex

I am looking for a regex that would indicate if there is a certain complete word in a text, for example for the word "cto":

• "i am a cto" - true
• "i am a cto/developer" - true
• 开发者_如何学Go"cto" - true
• "i am a cto_developer" - true
• "ctools" - false

I want the word to be case insensitive. Any thoughts?

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(?<=^|[^a-zA-Z0-9])<word>(?=$|[^a-zA-Z0-9])

Finds instances of <word> that are only preceded or succeeded by beginning or end of line/string or characters a-z or numbers 0-9. Example from RegexHero.

It would help if we knew what language this is in.

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You could either write an expression considering all the possibilities or use the \b anchor like \bmyWord\b and consider the _ a lost case because it's handled as part of the word so the "i am a cto_developer" will also return false.