So sati has one meaning of recollection, remembrance given for example there:
So far so good. But this is not the only meaning of sati as it has been declared, and so on the ground that there is no other definition of sati in the suttas.ariyasāvako satimā hoti parama sati-nepakkena samannāgato, cira-katam-pi cirabhāsitam-pi saritā anussaritā.
a noble disciple is mindful, endowed with excellent sati and carefulness, he recalls and remembers what was done, what was said long ago.
http://www.suttapitaka.net/sutta/angutt ... .html#sati" onclick="window.open(this.href);return false;
But there is a well-known definition of samma-sati:
Here it is very clear that samma-sati is a presence of the mind applied to what happens in the present moment in body, feeling, mind and mental phenomena.Katamā ca, bhikkhave, sammāsati? Idha, bhikkhave, bhikkhu kāye kāyānupassī viharati ātāpī sampajāno satimā, vineyya loke abhijjhā-domanassaṃ; vedanāsu vedanānupassī viharati ātāpī sampajāno satimā, vineyya loke abhijjhā-domanassaṃ; citte cittānupassī viharati ātāpī sampajāno satimā, vineyya loke abhijjhā-domanassaṃ; dhammesu dhammānupassī viharati ātāpī sampajāno satimā, vineyya loke abhijjhā-domanassaṃ.
"And what, monks, is right mindfulness? (i) There is the case where a monk remains focused on the body in & of itself — ardent, aware, & mindful — putting away greed & distress with reference to the world. (ii) He remains focused on feelings in & of themselves — ardent, aware, & mindful — putting away greed & distress with reference to the world. (iii) He remains focused on the mind in & of itself — ardent, aware, & mindful — putting away greed & distress with reference to the world. (iv) He remains focused on mental qualities in & of themselves — ardent, aware, & mindful — putting away greed & distress with reference to the world. This, monks, is called right mindfulness."
http://www.accesstoinsight.org/tipitaka ... .than.html" onclick="window.open(this.href);return false;
Now samma-sati is a particular type of sati. So the definition of sati must be wider than the definition of samma-sati. Therefore the definition of sati must include this definition.
So sati has at least two meanings: recollection/remembrance and presence of the mind in the reality of mind and matter.
[Edit 30 Nov 2554:]
And most importantly, in the context of meditation practice like anapanassati or satipatthana, it is evident that sati should be as close as possible to samma-sati, so it is the second definition that applies in this case.
The relation between these two meanings of sati is explained here:
These two meanings are related in the sense that an awareness supported by the collectedness of concentration is a necessary condition to get proper perception and understanding of what is happening in the present moment, which enables an easy recollection at a later time of what precisely was happening, of what was said, what was done at a prior moment, even a long time before. In one case sati is defined as per what is happening in the present moment, and in the other as per the qualities that develop in the bhikkhu when he has been endowed with this awareness of the present moment for a long time.
http://www.suttapitaka.net/glossary.html#sati" onclick="window.open(this.href);return false;