Vocabulary Builder: Adventitious

Long Definition:

ad·ven·ti·tious      /?æd v?n?t???s/ Pronunciation Key – Show Spelled Pronunciation[ad-vuh n-tish–uhs] Pronunciation Key – Show IPA Pronunciation

–adjective

1.	associated with something by chance rather than as an integral part; extrinsic.

2.	Botany, Zoology. appearing in an abnormal or unusual position or place, as a root.

---

[Origin: 1595–1605; < L advent?cius lit., coming from without, external, equiv. to ad- ad- + ven- (s. of ven?re to come) + -t(us) ptp. suffix + -?cius -itious ]

—Related forms

ad·ven·ti·tious·ly, adverb

ad·ven·ti·tious·ness, noun

Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.

Short Definition:  abnormal

Sentences:
His arrogant behavior today was adventitous; he's normally quite humble and polite.
We found a small gemstone in the mine, but it's presence must be adventitious as this region is not known for such gems.

Mnemonic:
Hat vent tissues > ape snore mole – The Cat in the Hat's hat is so tall it has vents on the side to help with circulation.  The cat carries around a gigantic box of tissues to wipe the vents clean.  He can't reach the vents while he's wearing the hat, however, so he's followed by a trained purple ape who sounds like he's constantly snoring.  However, when you look closely, you notice that the snoring is coming from a giant hairy mole on the side of the ape's neck (that's an adventitious mole).
With this word, the short definition is so abstract that I encoded it with a mnemonic as well.