"somewhat depressed," 1706, from hip (n.) "melancholy," variant of hyp, short for hypochondria.
Examples from the Web for hippish
Historical Examples of hippish
And she might be hippish and drooping for a longer time, and be no less easily at last cured.Six Discourses on the Miracles of our Saviour
I want something of another cast; something that will urge me when I am hippish, without keeping me in order when I am whimsical.The Wanderer (Volume 3 of 5)