lhag bcas myang 'das - Nirvana with Remainder

lhag bcas myang 'das means Nirvana with remainder.

lhag here means residue. bcas is another good particle you should try to recognize this one, it's used in combination with other words to bind them together, so it's together with. The whole expression lhag bcas means physical residue, in other words the body we have in Samsara.

myang 'das means Nirvana.

This Nirvana is Nirvana with remainder. Even if the person has achieved exhaustion of all mental afflictions in his or her mind stream, the body -- part of past karma that has to still trigger in the mind stream -- is present. So this defines the state of someone who has reached Nirvana, but is still occupying a body, until the karmic causes for the existence of this body are exhausted.