tatpuruṣa

The tatpuruṣa is a versatile compound whose first member desribes its second:

• राज्ञः पुत्रः → राजपुत्रः
  rājñaḥ putraḥ → rājaputraḥ
  the king's son; a prince
  

adhikāra rules

Most of the system's samāsa rules are specifically about the tatpuruṣa. These rules are within the scope of the following two adhikāra rules:

• विभाषा। २.१.११
  vibhāṣā (2.1.11)
  vibhāṣā
  Optionally, ...

• तत्पुरुषः। २.१.२२
  tatpuruṣaḥ (2.1.22)
  tatpuruṣaḥ
  ... is a tatpuruṣa.

The first rule states that the tatpuruṣa is optional. For example, both rājñaḥ putraḥ and rājaputraḥ express the same semantics. In comparison, the avyayībhāva is an obligatory (nitya) compound; we cannot break the compound into separate words while keeping the same semantics.

The second rule, meanwhile, just states that the following rules define a tatpuruṣa.

The tatpuruṣa with different vibhaktis

Generally, the first word of the tatpuruṣa can appear in any vibhakti in relation to the second. But some of these vibhaktis are more restricted than others:

• द्वितीया श्रितातीतपतितगतात्यस्तप्राप्तापन्नैः। २.१.२४
  dvitīyā śritātītapatitagatātyastaprāptāpannaiḥ (2.1.24)
  dvitīyā śrita-atīta-patita-gata-atyasta-prāpta-āpannaiḥ
  [A subanta ending in] the second (vibhakti used with the words) śrita, atīta, patita, gata, atyasta, prāpta, āpanna [optionally creates a tatpuruṣa].

• तृतीया तत्कृतार्थेन गुणवचनेन। २.१.३०
  tṛtīyā tatkṛtārthena guṇavacanena (2.1.30)
  tṛtīyā tat-kṛta-arthena guṇa-vacanena
  [Likewise for a subanta ending in] the third (vibhakti) with a word denoting a quality (guṇavacana) when it is the cause of it becoming so;

• कर्तृकरणे कृता बहुलम्। २.१.३२
  kartṛkaraṇe kṛtā bahulam (2.1.32)
  kartṛ-karaṇe kṛtā bahulam
  [a subanta ending in] the third (vibhakti), variously, with a kṛt in the sense of kartṛ (agent) or karaṇa (instrument);

• चतुर्थी तदर्थार्थबलिहितसुखरक्षितैः। २.१.३६
  caturthī tadarthārthabalihitasukharakṣitaiḥ (2.1.36)
  caturthī tadartha-artha-bali-hita-sukha-rakṣitaiḥ
  [a subanta ending in] the fourth (vibhakti) with [a subanta] denoting the reason, or that is the word artha, bali, hita, sukha, or rakṣita;

• पञ्चमी भयेन। २.१.३७
  pañcamī bhayena (2.1.37)
  pañcamī bhayena
  [a subanta ending in] the fifth (vibhakti) with the word bhaya (fear);

• सप्तमी शौण्डैः। २.१.४०
  saptamī śauṇḍaiḥ (2.1.40)
  saptamī śauṇḍaiḥ
  [a subanta ending in] the seventh (vibhakti when used with the words in the list starting with) śauṇḍa;

Examples:

• शरणं गतः → शरणगतः
  śaraṇaṃ gataḥ → śaraṇagataḥ
  gone to shelter (2.1.24)
  

• शङ्कुलया खण्डः → शङ्कुलाखण्डः
  śaṅkulayā khaṇḍaḥ → śaṅkulākhaṇḍaḥ
  a piece (cut off) by shears (2.1.30)
  

• अग्निना दग्धः → अग्निदग्धः
  agninā dagdhaḥ → agnidagdhaḥ
  burned by the fire (2.1.32)
  

• कुण्डलाय हिरण्यम् → कुण्डलहिरण्यम्
  kuṇḍalāya hiraṇyam → kuṇḍalahiraṇyam
  gold for earrings (2.1.36)
  

• चौरात् भयम् → चौरभयम्
  caurāt bhayam → caurabhayam
  fear from thieves (2.1.37)
  

• अक्षेषु शौण्ड → अक्षषौण्ड
  akṣeṣu śauṇḍa → akṣaṣauṇḍa
  fond of dice (2.1.40)
  

In comparison, the first and sixth vibhaktis are less restricted. The sixth vibhakti has no restriction at all:

• षष्ठी। २.२.८
  ṣaṣṭhī (2.2.8)
  ṣaṣṭhī
  [A subanta ending in] the sixth (vibhakti) [optionally creates a tatpuruṣa].

And the first vibhakti is acceptable whenever the first word qualifies the second in some way:

• विशेषणम् विशेष्येण बहुलम्। २.१.५७
  viśeṣaṇam viśeṣyeṇa bahulam (2.1.57)
  viśeṣaṇam viśeṣyeṇa bahulam
  An adjective with its qualified term variously [forms a tatpuruṣa].

Examples:

• राज्ञः पुत्रः → राजपुत्रः
  rājñaḥ putraḥ → rājaputraḥ
  the king's son; a prince (2.2.8)
  

• नीलः उत्पलः → नीलोत्पलः
  nīlaḥ utpalaḥ → nīlotpalaḥ
  blue water lily (2.1.57)