An old word — both characters appear together in 《东观汉记·王霸传》 (Han dynasty), where Wang Ba is jeered at by 'people in the marketplace, all bursting into laughter and lifting hands to ridicule (揶揄) him.' The meaning hasn't shifted in 2000 years.
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Literary, slightly old-fashioned. Spoken Chinese prefers 嘲笑 (cháoxiào) or 取笑 (qǔxiào). 揶揄 implies a more pointed, witty mockery rather than crude teasing.
