heterogeneous

Concise Oxford English Dictionary © 2008 Oxford University Press:
heterogeneous /ˌhɛt(ə)rə(ʊ)ˈdʒiːnɪəs, -ˈdʒɛn-/

▶adjective

• 1 diverse in character or content.

• 2 Chemistry denoting a process involving substances in different phases (solid, liquid, or gaseous): heterogeneous catalysis.

– derivatives
heterogeneity /-dʒɪˈniːɪti, -ˈneɪɪti/ noun,
heterogeneously adverb,
heterogeneousness noun.

– origin C17: from med. L. heterogeneus, from Gk heterogenēs, from heteros ‘other’ + genos ‘a kind’.

usage: Heterogeneous is commonly misspelled as heterogenous. Heterogenous is actually a different word, meaning ‘originating outside the organism’.