bahuvrīhi

Generally, the bahuvrīhi is a compound whose members describe a third idea that is not explicitly stated:

• बहुव्रीहिः (स्त्री)
  bahuvrīhiḥ (strī)
  (a woman) who has much rice
  

The bahuvrīhi is much less complicated than the tatpuruṣa, and we can account for most of its behavior with just a few rules:

• शेषो बहुव्रीहिः। २.२.२३
  śeṣo bahuvrīhiḥ (2.2.23)
  śeṣaḥ bahuvrīhiḥ
  The remaining samāsas are called bahuvrīhi.

• अनेकमन्यपदार्थे। २.२.२४
  anekamanyapadārthe (2.2.24)
  anekam anya-pada-arthe
  Many related (padas) denoting a separate pada [optionally become a bahuvrīhi].

• तेन सहेति तुल्ययोगे। २.२.२८
  tena saheti tulyayoge (2.2.28)
  tena saha iti tulya-yoge
  The word saha [with a subanta] that has the same relation to the action (as the word it describes) [optionally becomes a bahuvrīhi].

Examples:

• महान् रथो यस्य → महारथः
  mahān ratho yasya → mahārathaḥ
  whose chariot is great (2.2.24)
  

• सपुत्रः (आगतः)
  saputraḥ (āgataḥ)
  (came) with his son (2.2.28)