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.
Entry नाय
नायnāyaA leader, guide.
[नी-कर्तरि ण]
A leader, guide.
Guiding, directing.
Policy, prudence; यात यूयं यमश्रायं दिशं नायेन दक्षिणाम् Bk.7.36.
Means, expedient; नायः कोऽत्र स येन स्यां बताहं विगतज्वरः Bk.6.82.