Synonyms of the word

adventitious

• adj. From an external source; not innate or inherent, foreign.
• adj. Accidental, additional, appearing casually.
• adj. (genetics, medicine) Not congenital; acquired.
• adj. (biology) Developing in an unusual place or from an unusual source.

accidental

• adj. Not essential; incidental, secondary.
• adj. (philosophy) Nonessential to something's inherent nature (especially in Aristotelian thought).
• adj. (music) Adjusted by one or two semitones, in temporary departure from the key signature.
• adj. Occurring sometimes, by chance; occasional.
• adj. Happening by chance, or unexpectedly; taking place not according to the usual course of things; by accident,…
• adj. (geometry) Being a double point with two distinct tangent planes in 4-dimensional projective space.
• n. A property which is not essential; a nonessential; anything happening accidentally.
• n. (painting, plural only) Those fortuitous effects produced by luminous rays falling on certain objects…
• n. (music) A sharp, flat, or natural, occurring not at the commencement of a piece of music as the signature,…

extrinsic

• adj. external, separable from the thing itself, inessential.
• adj. not belonging to, outside of.