The word "gotra" means "lineage" in the Sanskrit

Sanskrit

Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...

 language. Among those of the Brahmin

Brahmin

Brahmin Brahman, Brahma and Brahmin.Brahman, Brahmin and Brahma have different meanings. Brahman refers to the Supreme Self...

 caste

Caste

Caste is an elaborate and complex social system that combines elements of endogamy, occupation, culture, social class, tribal affiliation and political power. It should not be confused with race or social class, e.g. members of different castes in one society may belong to the same race, as in India...

, gotras are reckoned patrilineally. Each gotra takes the name of a famous Rishi

Rishi

Rishi denotes the composers of Vedic hymns. However, according to post-Vedic tradition, the rishi is a "seer" to whom the Vedas were "originally revealed" through states of higher consciousness. The rishis were prominent when Vedic Hinduism took shape, as far back as some three thousand years...

 or sage who was the patrilineal forebearer of that clan. And each Gotra is addressed by the suffix 'sa' or 'asa' as relevant.

The concept of Gotra

Gotra

In the Hindu society, the term Gotra broadly refers to people who are descendants in an unbroken male line from a common male ancestor. Panini defines gotra for grammatical purposes as apatyam pautraprabhrti gotram , which means "the word gotra denotes the progeny beginning with the son's son"...

 was the first attempt among Brahmin

Brahmin

Brahmin Brahman, Brahma and Brahmin.Brahman, Brahmin and Brahma have different meanings. Brahman refers to the Supreme Self...

s to classify themselves among different groups.