महाभारतः mahābhārataḥ - book-5, chapter-159, verse-4

अवाक्शिरा भीमसेनः समुदैक्षत केशवम् ।
नेत्राभ्यां लोहितान्ताभ्यामाशीविष इव श्वसन् ॥४॥

4. avākśirā bhīmasenaḥ samudaikṣata keśavam ,
netrābhyāṁ lohitāntābhyāmāśīviṣa iva śvasan.

4. avāk-śirāḥ bhīmasenaḥ sam-ud-aikṣata keśavam
netrābhyām lohita-antābhyām āśīviṣaḥ iva śvasan

4. avāk-śirāḥ bhīmasenaḥ netrābhyām lohita-antābhyām āśīviṣaḥ iva śvasan keśavam sam-ud-aikṣata.

4. Bhīmasena, with his head bowed, looked up at Keśava (Kṛṣṇa). His eyes were red at the corners, and he was hissing like a venomous snake.

Words meanings summery:

• अवाक्-शिराः (avāk-śirāḥ) - with downcast head, with head bent low

• भीमसेनः (bhīmasenaḥ) - Bhīmasena, son of Pāṇḍu and Kuntī (by the grace of Vāyu)

• सम्-उद्-ऐक्षत (sam-ud-aikṣata) - he looked up, he gazed up

• केशवम् (keśavam) - Kṛṣṇa (Keśava (an epithet of Kṛṣṇa))

• नेत्राभ्याम् (netrābhyām) - with two eyes, by two eyes

• लोहित-अन्ताभ्याम् (lohita-antābhyām) - with red corners, having red extremities

• आशीविषः (āśīviṣaḥ) - venomous snake, serpent

• इव (iva) - like, as, as if

• श्वसन् (śvasan) - hissing (like a snake) (hissing, breathing, sighing)

Words meanings and morphology

अवाक्-शिराः (avāk-śirāḥ) - with downcast head, with head bent low

(adjective)

Nominative, masculine, singular of avāk-śiras

avāk-śiras - having the head bent down, down-headed

Compound type : bahuvrihi (avāk+śiras)

• avāk – downward, downwards, low
  indeclinable
• śiras – head
  noun (neuter)

भीमसेनः (bhīmasenaḥ) - Bhīmasena, son of Pāṇḍu and Kuntī (by the grace of Vāyu)

(proper noun)

Nominative, masculine, singular of bhīmasena

bhīmasena - one of the Pāṇḍava brothers, a renowned warrior

Compound of Bhīma (terrible) and Sena (army, chief).

Compound type : tatpurusha (bhīma+sena)

• bhīma – terrible, formidable, dreadful
  adjective (masculine)
• sena – army, host, chieftain
  noun (masculine)

सम्-उद्-ऐक्षत (sam-ud-aikṣata) - he looked up, he gazed up

(verb)

3rd person , singular, middle, imperfect (laṅ) of √īkṣ

Prefixes: sam+ud

Root: īkṣ (class 1)

केशवम् (keśavam) - Kṛṣṇa (Keśava (an epithet of Kṛṣṇa))

(proper noun)

Accusative, masculine, singular of keśava

keśava - having beautiful long hair; a name of Viṣṇu or Kṛṣṇa

नेत्राभ्याम् (netrābhyām) - with two eyes, by two eyes

(noun)

Instrumental, neuter, dual of netra

netra - eye, leader, guide

Derived from root √nī (to lead) with suffix -tra.

Root: nī (class 1)

लोहित-अन्ताभ्याम् (lohita-antābhyām) - with red corners, having red extremities

(adjective)

Instrumental, neuter, dual of lohita-anta

lohita-anta - red at the extremities/corners

Compound type : tatpurusha (lohita+anta)

• lohita – red, reddish, bloody
  adjective (masculine)
• anta – end, extremity, border, corner
  noun (masculine)

आशीविषः (āśīviṣaḥ) - venomous snake, serpent

(noun)

Nominative, masculine, singular of āśīviṣa

āśīviṣa - a serpent whose poison is in its fangs, venomous snake

Compound of āśī (fang) and viṣa (poison).

Compound type : bahuvrihi (āśī+viṣa)

• āśī – fang, serpent's tooth
  noun (feminine)
• viṣa – poison, venom
  noun (neuter)

इव (iva) - like, as, as if

(indeclinable)

श्वसन् (śvasan) - hissing (like a snake) (hissing, breathing, sighing)

(adjective)

Nominative, masculine, singular of śvasat

śvasat - breathing, hissing, sighing

Present Active Participle

Derived from root √śvas (to breathe, to hiss) with śatṛ (present active participle) suffix.

Root: śvas (class 2)