Yoga
Yoga literally means 'linking', and typically (as in Raja Yoga) this means linking or combining with God (i.e. 'union', from the sanskrit meaning yoke). For BKs, yoga means meditation and remembrance i.e. remembering God. One can have yoga (i.e. soul to soul communion) with any soul but BKs are severely discouraged from having yoga with any souls other than their Supreme Soul i.e. Shiva.
The BK flavour of yoga, Raja Yoga is mental and not physical and is described under Raja Yoga
One of the four main BK subjects, ie yoga, gyan, seva, and dharna.