ABB pattern adjective:
懒 (lǎn, 'lazy') + reduplicated
洋洋 = a vivid descriptive form. The reduplicated suffix
洋洋 also appears in
喜洋洋 (xǐyāngyāng, 'cheerful'),
暖洋洋 (nuǎnyāngyāng, 'pleasantly warm'),
得意洋洋 (déyì yāngyāng, 'smugly pleased') — it's a productive intensifier suggesting an overflowing, pervasive quality.
