thinkest

• think'st (obsolete)
• thinkst

think +‎ -est.

thinkest

1. (archaic) second-person singular simple present indicative of think
   • 1886 October – 1887 January, H[enry] Rider Haggard, She: A History of Adventure, London: Longmans, Green, and Co., published 1887, →OCLC:

     "How thinkest thou that I rule this people? I have but a regiment of guards to do my bidding, therefore it is not by force. It is by terror."

• stinketh