mindful

Short definition from Wiktionary

Adjective

1. 1
   aware (of something); attentive, heedful.
2. 2
   Of or pertaining to mindfulness; sustaining meta-attention of the contents of one's own mind in the present moment.
3. 3
   Inclined (to do something).

Noun

1. 1
   As much as can be held in one's mind at a time.