无心 is a verb-object compound (离合词) meaning either 'not in the mood (to do something)' or 'unintentionally / inadvertently'. In the first sense it is often followed by a verb (无心工作 'not in the mood to work'); in the second it modifies an action (无心之言 'an unintentional remark'). As a separable verb, you can insert a modifier between 无 and 心, e.g. 无半点心 ('not have the slightest intention'). Note: the standard pronunciation is wú xīn, though the source data lists 'mó' — this is likely an error.