Incompatible \In`com*pat"i*ble\, n. (Med. & Chem.) An incompatible substance; esp., in pl., things which can not be placed or used together because of a change of chemical composition or of opposing medicinal qualities; as, the incompatibles of iron.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Incompatible \In`com*pat"i*ble\, a. [Pref. in- not + compatible: cf. F. incompatible.]

[It was formerly sometimes written incompetible.]

1. Not compatible; so differing as to be incapable of harmonious combination or coexistence; inconsistent in thought or being; irreconcilably disagreeing; as, persons of incompatible tempers; incompatible colors, desires, ambition.

A strength and obduracy of character incompatible with his meek and innocent nature. --Southey.

Source: Webster's Revised Unabridged Dictionary (1913)