Basic Meaning
This is the meditation of directly observing the mind without engaging in any analytical or intellectual activity. (Thrangu Rinpoche, Transcending Ego, 102).
Has the sense of
Also called "settling meditation" (Skt. sthāpyabhāvanā; Tib. འཇོག་སྒོམ་, jokgom or jok gom, Wyl. 'jog sgom)—the counterpart of analytical meditation. The practice of settling or resting the mind, which is alternated with periods of analysis or visualization.
Ringu Tulku Rinpoche says:
"Whenever we reach a conclusion, or simply get tired, we just remain, settled in peace. This part is a little like shamatha." (Source: Rigpa Wiki)
"In placement meditation one goes directly into deep Shamatha meditation and then one "looks at mind" directly without any analysis and perceives its emptiness." (Thrangu Rinpoche, Transcending Ego, 86).
Discussion of the term
Note that there is a Sanskrit term, sthāpyabhāvanā, sometimes referred to in research for this Tibetan word, but according to The Princeton Dictionary of Buddhism, it appears to be a back-translation or unattested Sanskrit equivalent.