هجس1 هَجَسَ الشَّىْءُ فِى قَلْبِهِ, (A,) or فِى صَدْرِهِ, (K,) or بِالقَلْبِ, (Msb,) aor. ـِ (S, K, MS, TA,) or ـُ (Msb,) inf. n. هَجْسٌ, (Msb, TA,) The thing fell into, or occurred to, or bestirred itself in, his mind, or the mind; or occurred to his mind, or the mind, after having been for-gotten; syn. وَقَعَ and خَطَرَ; (Msb;) or, of the phrase in the A and that in the K, خَطَرَ بِبَالِهِ, (A, K,) and وَقَعَ فِى خَلَدِهِ: (TA:) or هَجْسٌ signifies [the thing's] talking, or suggesting something, to the person's mind, in his bosom; expl. by the words أَنْ يُحَدِّثَ نَفْسَهُ فِى صَدْرِهِ; like  وِسْوَاسٌ: (K, * TA:) and hence the phrase in a trad., وَمَا يَهْجِسُ فِى الضَّمَائِرِ, meaning, and what falls into, or occurs in, and bestirs itself in, the minds, (يَخْطُرُ بِهَا,) and revolves therein, of matters of discourse, and of thoughts: (TA:) or هَجَسَ فِى صَدْرِى شَىْءٌ signifies i. q. حَدَسَ [app. meaning a thing came at random into my mind]: (S, L:) and you say also, هَجَسَ فى نَفْسِى[it fell into, or occurred to, my mind: &c.] (TA.) 5 تَهَجَّسَ I. q. أَقَامَ. (T, art. عرص.) هَجْسٌ A low voice, or sound, (نَبْأَةٌ,) which  one hears but does not understand. (S.) b2: See also هَاجِسٌ.هَاجِسٌ A thing, or an idea, or object of thought, or an opinion, coming at random into, falling into, occurring to, or bestirring itself in, the mind; (S, A, * Msb;) syn. خَاطِرٌ: (S, TA:) an epithet in which the quality of a subst predominates: (TA:) and ↓ هَجْسٌ also signifies anything falling into, or occurring to, the mind; (Lth, K:) pl. of the former, هَوَاجِسُ. (A, TA.)