before vowels encephal-, word-forming element meaning "brain, of the brain," from combining form of medical Latin encephalon, from Greek enkephalos "the brain," literally "within the head," from en "in" (see en- (2)) + kephalē "head" (see cephalo-).

"inflammation of the brain," 1843, from encephalo- "the brain" + -itis "inflammation." Related: Encephalitic.

1934, from electro- + encephalo-, combining form of Modern Latin encephalon "brain" (see encephalitis) + -gram.