V. S. Apte, The Practical Sanskrit–English Dictionary. Look up any word of the Gita in Devanagari, IAST or Harvard-Kyoto, or browse the headwords letter by letter.
vimṛśyaitadaśeṣeṇa yathecchasi tathā kuru. — So have I expounded to thee a knowledge more secret than that which is hidden; having reflected on it fully, do as thou wouldest. 18·63
विमृश्यvimṛśyaindeclinable past participle or gerund form of the verbal root mṛś (to consider, reflect, deliberate) with the prefix vi.