Conjointly and For certain

Conjointly adverb - In or by combined action or effort.

For certain and conjointly are semantically related. In some cases you can use "For certain" instead an adverb "Conjointly".

For certain adverb - Definitely or positively (`sure' is sometimes used informally for `surely').

Conjointly and for certain are semantically related. Sometimes you can use "Conjointly" instead an adverb phrase "For certain".