महाभारतः mahābhārataḥ - book-3, chapter-33, verse-40

अनर्थं संशयावस्थं वृण्वते मुक्तसंशयाः ।
धीरा नराः कर्मरता न तु निःसंशयं क्वचित् ॥४०॥

40. anarthaṁ saṁśayāvasthaṁ vṛṇvate muktasaṁśayāḥ ,
dhīrā narāḥ karmaratā na tu niḥsaṁśayaṁ kvacit.

40. anartham saṃśayāvastham vṛṇvate muktasaṃśayāḥ
dhīrāḥ narāḥ karmaratāḥ na tu niḥsaṃśayam kvacit

40. Wise and resolute individuals, who are committed to action (karma) and free from doubt, choose to undertake tasks that may appear disadvantageous or uncertain to others. Yet, they never truly choose anything that is unquestionably without benefit.

Words meanings summery:

• अनर्थम् (anartham) - a task or situation that appears disadvantageous or uncertain to others (misfortune, adversity, a useless or unprofitable thing/task)

• संशयावस्थम् (saṁśayāvastham) - a task or situation that is in a doubtful state (in a state of doubt, uncertain)

• वृण्वते (vṛṇvate) - they choose, they select, they undertake

• मुक्तसंशयाः (muktasaṁśayāḥ) - resolute individuals who are certain of their success (those freed from doubt, those whose doubts are dispelled)

• धीराः (dhīrāḥ) - wise, resolute, brave, firm

• नराः (narāḥ) - men, people, human beings

• कर्मरताः (karmaratāḥ) - committed to their duties and responsibilities (devoted to action, engaged in action)

• न (na) - not, no

• तु (tu) - but, on the other hand, indeed

• निःसंशयम् (niḥsaṁśayam) - without doubt, certainly, undoubtedly

• क्वचित् (kvacit) - ever, at any time, sometimes, in some way

Words meanings and morphology

अनर्थम् (anartham) - a task or situation that appears disadvantageous or uncertain to others (misfortune, adversity, a useless or unprofitable thing/task)

(noun)

Accusative, masculine, singular of anartha

anartha - misfortune, evil, adversity, something useless or without profit

Compound type : nañ-tatpuruṣa (an+artha)

• an – not, non-
  indeclinable
  Negative prefix
• artha – purpose, meaning, wealth, advantage, thing
  noun (masculine)

संशयावस्थम् (saṁśayāvastham) - a task or situation that is in a doubtful state (in a state of doubt, uncertain)

(adjective)

Accusative, masculine, singular of saṃśayāvastha

saṁśayāvastha - being in a state of doubt, uncertain

Compound type : ṣaṣṭhī-tatpuruṣa (saṃśaya+avastha)

• saṃśaya – doubt, uncertainty, hesitation
  noun (masculine)
  Prefix: sam
• avastha – standing, being in a state, situated
  adjective (masculine)
  From avasthā (state) or Past Passive Participle of ava√sthā
  Prefix: ava

Note: Modifies 'anartham'.

वृण्वते (vṛṇvate) - they choose, they select, they undertake

(verb)

3rd person , plural, middle, present indicative (lat) of √vṛ

Root: vṛ (class 9)

मुक्तसंशयाः (muktasaṁśayāḥ) - resolute individuals who are certain of their success (those freed from doubt, those whose doubts are dispelled)

(adjective)

Nominative, masculine, plural of muktasaṃśaya

muktasaṁśaya - one whose doubt is released/removed, free from doubt

Compound type : bahuvrīhi (mukta+saṃśaya)

• mukta – freed, released, liberated
  participle (masculine)
  Past Passive Participle
  Formed from √muc (to release, free).
  Root: muc (class 6)
• saṃśaya – doubt, uncertainty, hesitation
  noun (masculine)
  Prefix: sam

धीराः (dhīrāḥ) - wise, resolute, brave, firm

(adjective)

Nominative, masculine, plural of dhīra

dhīra - wise, resolute, brave, firm, steady

नराः (narāḥ) - men, people, human beings

(noun)

Nominative, masculine, plural of nara

nara - man, person, human being

कर्मरताः (karmaratāḥ) - committed to their duties and responsibilities (devoted to action, engaged in action)

(adjective)

Nominative, masculine, plural of karma-rata

karma-rata - devoted to action, engaged in work/duty

Compound type : saptamī-tatpuruṣa (karma+rata)

• karma – action, deed, work, duty (karma)
  noun (neuter)
• rata – devoted, engaged, attached to, pleased
  participle (masculine)
  Past Passive Participle
  Formed from √ram (to delight, to be pleased).
  Root: ram (class 1)

न (na) - not, no

(indeclinable)

तु (tu) - but, on the other hand, indeed

(indeclinable)

निःसंशयम् (niḥsaṁśayam) - without doubt, certainly, undoubtedly

(indeclinable)

Compound type : prādi-samāsa (nis+saṃśaya)

• nis – out, forth, without, negation
  indeclinable
  Prefix indicating negation or absence.
• saṃśaya – doubt, uncertainty, hesitation
  noun (masculine)
  Prefix: sam

Note: Adverbial form (neuter accusative singular used as an adverb).

क्वचित् (kvacit) - ever, at any time, sometimes, in some way

(indeclinable)