استثقلهُ
1.
opposite of
اِسْتَخَفَّهُ; (S and K and TA in article خف;) He deemed it, or him,
ثَقِيل [i. e. heavy, properly and tropically]. (TA in that article)
2.
[Hence, (assumed tropical:) He deemed it (a word or a sound) heavy, or not easy, of utterance; or heavy to the ear: often occurring in this sense in lexicons and grammars.]
3.
اُسْتُثْقِلَ نَوْمًا (assumed tropical:) [He was overcome, and rendered heavy, by sleep: and in like manner, مَرَضًا, by sickness or disease: and لُوءْمًا, by meanness or sordidness: see its pass. particle n., below]. (JK.)