The Proto-Indo-European word *st(h₂)eug-
Word *st(h₂)eug-
Meaning stiff
See also Proto-Indo-European: *(s)teh₂- ‘to stand’
Synonyms *(s)terh₁-

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*h₃em- ‘bitter’, *kwat- ‘sour’, *sweh₂d-u- ‘sweet’, *h₂em- ‘raw, bitter’, *suhₓros ‘sour, acid’, *h₂emros ‘bitter, sour’