3.16

एवं प्रवर्तितं चक्रं नानुवर्तयतीह यः ।
अघायुरिन्द्रियारामो मोघं पार्थ स जीवति ॥

evaṃ pravartitaṃ cakraṃ nānuvartayatīha yaḥ
aghāyur indriyārāmo moghaṃ pārtha sa jīvati

śrībhagavān (श्रीभगवान्) is speaking, and the chain of 3.14 and 3.15 gets its name, a wheel.

The verse

He who does not keep this wheel turning here lives in vain, Pārtha (पार्थ), a life of evil spent in the senses.

नेपालीमा

हे पार्थ, जसले यहाँ यो चक्र घुमाइरहँदैन, त्यो इन्द्रियमा पापको जीवन बिताउँदै व्यर्थ बाँच्छ।

Where it sits

The wheel is now a duty for anyone who still has a life to spend. 3.17 will name the exception, the person who no longer needs anything from the wheel.

Split: एवम् + प्रवर्तितम् + चक्रम् + न + अनुवर्तयति + इह + यः + अघ-आयुः + इन्द्रिय-आरामः + मोघम् + पार्थ + सः + जीवति

evam + pravartitam + cakram + na + anuvartayati + iha + yaḥ + agha-āyuḥ + indriya-ārāmaḥ + mogham + pārtha + saḥ + jīvati

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
एवम्evamindeclinablethus. As just described.
प्रवर्तितम्pravartitamaccusative neuterset going, set to turn.
चक्रम्cakramaccusativethe wheel.
नnaindeclinablenot.
अनुवर्तयतिanuvartayatipresent, 3rd singular, causativehe keeps it turning, he follows it along.
इहihaindeclinablehere.
यःyaḥnominativewho.
अघ-आयुःagha-āyuḥnominativehe whose life is evil. āyus (आयुस्) is life.
इन्द्रिय-आरामःindriya-ārāmaḥnominativehe whose delight is in the senses. ārāma (आराम) is a pleasure-garden.
मोघम्moghamaccusative, adverbialin vain.
पार्थpārthavocativePārtha (पार्थ), son of Pṛthā (पृथा). Arjuna (अर्जुन).
सःsaḥnominativehe.
जीवतिjīvatipresent, 3rd singularhe lives.

The phrases

एवम् प्रवर्तितम् चक्रम् न अनुवर्तयति इह यः evaṃ pravartitam cakraṃ na anuvartayati iha yaḥ is the refusal. Who, here, does not keep turning the wheel that has been set going. न + अनुवर्तयति + इह na + anuvartayati + iha is nānuvartayatīha (नानुवर्तयतीह). First अ + अ a + a lengthens, then इ + इ i + i lengthens.

aghāyuḥ indriyārāmaḥ (अघायुः इन्द्रियारामः) is the life that refusal makes. A life of evil, delighting in the senses. uḥ (उः) before a vowel becomes ur (उर्): aghāyur i (अघायुरि). Then ārāmaḥ (आरामः) before the voiced m (म्) of mogham (मोघम्) becomes ārāmo (आरामो).

मोघम् पार्थ स जीवति moghaṃ pārtha sa jīvati is the judgment on that life. He lives in vain. sa (स) is saḥ (सः) before a consonant, as in 3.7.

Sanskrit in this line

uḥ (उः) before a vowel becomes ur (उर्). अघायुः + इन्द्रिय agha-āyuḥ + indriya is recited aghāyur indriya (अघायुरिन्द्रिय). The visarga has become r (र्), and the vowel of āyus (आयुस्) stays u (उ). You will meet iḥ (इः) doing the same with r (र्) in the next verse.

Say it back

Name the wheel, then say what kind of life fails to turn it. If mogham (मोघम्) becomes "unhappy," stay here. The verse says the life is wasted.