绪 is a bound form (黏着语素) that cannot stand alone; it must combine with another character to form a word. Its core meanings are 'thread' or 'beginning' (as in 头绪 'thread of a matter' and 绪论 'introduction'), 'mood' or 'feeling' (as in 情绪 'emotion' and 心绪 'state of mind'), and less commonly 'remnants' (as in 绪余 'remainder'). Knowing these semantic clusters helps you infer the meaning of unfamiliar compounds containing 绪.