etymology of the word "Acharya"- Sanskrit

courtesy:https://www.quora.com/What-is-the-etymology-of-the-word-Acharya

As per Sanskrit grammar, the Sanskrit word 'acharya' (IAST ācārya, आचार्य) comes from the root a + √char (ā + √car) and the suffix ya (ṇyat).

The root a + √char (ā + √car) has several meanings, in this context it means one of the following—

1. "to go favourably towards"
2. "to serve"
3. "to perform, to conduct"

Accordingly the meanings of the word 'acharya' are

1. "One who disciples ('shishya'-s) go favourably towards, i.e. approach for learning"
2. "One who is served by the disciples"
3. "One who performs 'dharma', or has right conduct"

Acharya Veda Vyasa, image from Wikimedia Commons

Long answer

The complete etymology of the word ācārya as per Paninian grammar is—

ā + √car → ṛhalorṇyat‌ (3.1.124) → ā + car + ṇyat → tasya lopaḥ (1.3.9) → ā + car + ya → ata upadhāyāḥ (7.2.116) → ā + cār + ya → ācārya

आ + √चर् → ऋहलोर्ण्यत्‌ (३.१.१२४) → आ + चर् + ण्यत् → तस्य लोपः (१.३.९) → आ + चर् + य → अत उपधायाः (७.२.११६) → आ + चार् + य → आचार्य

The meaning of the root ā + √car are—

1. "to go favourably towards": ācarati ābhimukhyena gacchati (आचरति आभिमुख्येन गच्छति, Sāyaṇabhāṣya on Ṛgveda-saṃhitā 10.17.6), ācarati anukūlamābhimukhyena gacchati (आचरति अनुकूलमाभिमुख्येन गच्छति, Upasargārthacandrikā).
2. "to serve": ācaraṇīyaḥ sevya ācāryaḥ (आचरणीयः सेव्य आचार्यः, Kṣīrasvāmī's commentary on Amarakoṣa 2.7.7)
3. "to perform, to conduct": ācāraḥ paramo dharmaḥ (आचारः परमो धर्मः, Manusmṛti 1.108)

Accordingly the meanings of the word 'acharya' are—

1. "One who disciples ('shishya'-s) go favourably towards, i.e. approach for learning": ācaryate iti ācāryaḥ (आचर्यते इति आचार्यः, Bhānujidīkṣita's commentary on Amarakoṣa 2.7.7), i.e. śiṣyaiḥ ācaryate anukūlamābhimukhyena gamyate iti ācāryaḥ (शिष्यैः आचर्यते अनुकूलमाभिमुख्येन गम्यते इति आचार्यः).
2. "One who is served by the disciples": ācaraṇīyaḥ sevya ācāryaḥ (आचरणीयः सेव्य आचार्यः, Kṣīrasvāmī's commentary on Amarakoṣa 2.7.7), i.e. śiṣyaiḥ ācaraṇīyaḥ sevya ācāryaḥ (शिष्यैः आचरणीयः सेव्य आचार्यः).
3. "One who performs 'dharma', or has right conduct". svayamācarate yasmādācāram … ācāryastena cocyate (स्वयमाचरते यस्मादाचारम् … आचार्यस्तेन चोच्यते, Brahmāṇḍapurāṇa 1.32.32), i.e. ācāraṃ [dharmam] svayam ācarate yasmād … ācāryastena cocyate (आचारं [धर्मम्] स्वयम् आचरते यस्माद् … आचार्यस्तेन चोच्यते).

PS: Derivation as per Nirukta

In the beginning of Yāska's Nirukta, another etymology of the word ācārya is given from the root a + chi (ā + √ci, "to gather something" or "to make something grow"). Yāska says (1.4)—

ācāryaḥ kasmādācārya ācāraṃ grāhayati ācinoti arthān ācinoti buddhim iti vā

आचार्यः कस्मादाचार्य आचारं ग्राहयति आचिनोति अर्थान् आचिनोति बुद्धिम् इति वा

"Whence [the word] ācārya? He makes [disciples] understand ācāra (dharma), gathers the meanings [of scriptures], and makes the intellect [of the disciples] grow."

PPS: Definition as per Manusmṛti

In the Manusmṛti, the definition of acharya (ācārya) is—

upanīya tu yaḥ śiṣyaṃ vedamadhyāpayeddvijaḥ, sakalpaṃ sarahasyaṃ ca tamācāryaṃ pracakṣate (2.140)

उपनीय तु यः शिष्यं वेदमध्यापयेद्द्विजः, सकल्पं सरहस्यं च तमाचार्यं प्रचक्षते

Translation by Ganganath Jha:

"The Brāhmana who, having initiated a pupil, teaches him the Veda along with the Ritualistic and esoteric treatises,—him they call, 'Ācārya', 'Preceptor'."