'Nimitta': mark, sign; image; target, object; cause, condition. These meanings are used in, and adapted to, many contexts of which only the doctrinal ones are mentioned here.
1. 'Mental (reflex-) image', obtained in meditation. In full clarity, it will appear in the mind by successful practice of certain concentration-exercises and will then appear as vividly as if seen by the eye. The object perceived at the very beginning of concentration is called the preparatory image (parikamma-nimitta). The still unsteady and unclear image, which arises when the mind has reached a weak degree of concentration, is called the acquired image (uggaha-nimitta). An entirely clear and immovable image arising at a higher degree of concentration is the counter-image (paṭibhāga-nimitta). As soon as this image arises, the stage of neighbourhood (or access) concentration (upacāra-samādhi) is reached.
2. 'Sign of (previous) kamma' (kamma-nimitta) and 'sign of the future) destiny' (gati-nimitta); these arise as mental objects of the last karmic consciousness before death (maraṇ āsanna kamma.
Usages (1) and (2) are commentarial (s. App.). In Sutta usage, the term occurs, e.g. as:
3. 'Outward appearance': of one who has sense-control it is said- that "he does not seize upon the general appearance' of an object ('na' nimittaggāhī; M. 38, D. 2; expl. Vis I, 54f;
4. 'Object': the six objects, i.e. visual, etc. (rūpa-nimitta; S. XXII, 3). Also, when in explanation of animitta cetovimutti, signless deliverance of mind (s. cetovimutti vimokkha), it is said, sabbanimittānaṃ amanasikārā, it refers to the 6 sense-objects (Com. to M. 43 [[Saḷ'āyatanavagga-a'ṭṭ'hakathā]), and has therefore to be rendered "by paying no attention to any object (or object-ideas)." A pleasant or beautiful object (subha-nimitta, q.v.) is a condition to the arising of the hindrance of sense-desire; a 'repellent object' (paṭigha-nimitta) for the hindrance of ill-will; contemplation on the impurity of an object (asubha-nimitta; s. asubha) is an antidote to sense-desire.
5. In Pts.M. II, in a repetitive series of terms, nimitta appears together with uppādo (origin of existence), pavattaṃ (continuity of existence), and may then be rendered by 'condition of existence' (s. Path, 194f.).