महाभारतः mahābhārataḥ - book-1, chapter-96, verse-42

सोऽचिरेणैव कालेन अत्यक्रामन्नराधिप ।
वनानि सरितश्चैव शैलांश्च विविधद्रुमान् ॥४२॥

42. so'cireṇaiva kālena atyakrāmannarādhipa ,
vanāni saritaścaiva śailāṁśca vividhadrumān.

42. saḥ acireṇa eva kālena atyakrāmat narādhipa
vanāni saritaḥ ca eva śailān ca vividhadrumān

42. O lord of men, he (Bhishma) swiftly crossed forests, rivers, and mountains adorned with diverse trees.

Words meanings summery:

• सः (saḥ) - Referring to Bhishma. (he, that)

• अचिरेण (acireṇa) - swiftly, in a short time, without delay

• एव (eva) - indeed, only, certainly

• कालेन (kālena) - Together with 'acireṇa eva', implying 'in a very short time' or 'swiftly'. (by time, in time, within a period of time)

• अत्यक्रामत् (atyakrāmat) - Bhishma crossing various geographical features during his return journey. (he crossed, he passed over, he traversed)

• नराधिप (narādhipa) - Addressing an implied listener, likely Janamejaya. (O lord of men, O king)

• वनानि (vanāni) - forests, woods

• सरितः (saritaḥ) - rivers

• च (ca) - and

• एव (eva) - indeed, only, certainly

• शैलान् (śailān) - mountains, rocks

• च (ca) - and

• विविधद्रुमान् (vividhadrumān) - Describes the mountains Bhishma crossed. (having various trees, full of diverse trees)

Words meanings and morphology

सः (saḥ) - Referring to Bhishma. (he, that)

(pronoun)

Nominative, masculine, singular of tad

tad - that, he, she, it

अचिरेण (acireṇa) - swiftly, in a short time, without delay

(adjective)

Instrumental, neuter, singular of acira

acira - not long, swift, recent, fresh

formed with negation prefix 'a' + 'cira'

Compound type : bahuvrihi (a+cira)

• a – not, un-, in-
  prefix
• cira – long, prolonged (time)
  adjective (neuter)

एव (eva) - indeed, only, certainly

(indeclinable)

कालेन (kālena) - Together with 'acireṇa eva', implying 'in a very short time' or 'swiftly'. (by time, in time, within a period of time)

(noun)

Instrumental, masculine, singular of kāla

kāla - time, period, season

अत्यक्रामत् (atyakrāmat) - Bhishma crossing various geographical features during his return journey. (he crossed, he passed over, he traversed)

(verb)

3rd person , singular, active, imperfect past (laṅ) of ati-kram

Prefix: ati

Root: kram (class 1)

नराधिप (narādhipa) - Addressing an implied listener, likely Janamejaya. (O lord of men, O king)

(noun)

Vocative, masculine, singular of narādhipa

narādhipa - lord of men, king

Compound type : tatpurusha (nara+adhipa)

• nara – man, human being
  noun (masculine)
• adhipa – lord, ruler, king
  noun (masculine)

वनानि (vanāni) - forests, woods

(noun)

Accusative, neuter, plural of vana

vana - forest, wood, grove, thicket

सरितः (saritaḥ) - rivers

(noun)

Accusative, feminine, plural of sarit

sarit - river, stream

च (ca) - and

(indeclinable)

एव (eva) - indeed, only, certainly

(indeclinable)

शैलान् (śailān) - mountains, rocks

(noun)

Accusative, masculine, plural of śaila

śaila - mountain, rock, hill

च (ca) - and

(indeclinable)

विविधद्रुमान् (vividhadrumān) - Describes the mountains Bhishma crossed. (having various trees, full of diverse trees)

(adjective)

Accusative, masculine, plural of vividhadruma

vividhadruma - having various trees, diverse-treed

Compound type : bahuvrihi (vividha+druma)

• vividha – various, diverse, manifold, different
  adjective (masculine)
• druma – tree, plant
  noun (masculine)

Note: Qualifies 'śailān'.