Merriam-Webster reads:

_{Main Entry: liq·ui·date Pronunciation: \ˈli-kwə-ˌdāt
Function: verb Inflected Form(s): liq·ui·dat·ed; liq·ui·dat·ing Etymology: Late Latin liquidatus, past participle of liquidare to melt, from Latin liquidus Date: circa 1575 transitive verb 1 a (1) : to determine by agreement or by litigation the precise amount of (indebtedness, damages, or accounts) (2) : to determine the liabilities and apportion assets toward discharging the indebtedness of b : to settle (a debt) by payment or other settlement 2 archaic : to make clear 3 : to do away with 4 : to convert (assets) into cash intransitive verb 1 : to liquidate debts, damages, or accounts 2 : to determine liabilities and apportion assets toward discharging indebtedness}

Dissidents were all liquidated or driven into exile.

Where does this connotation of the verb 'liquidate' come from?

Merriam-Webster reads:

_{Main Entry: liq·ui·date
Pronunciation: \ˈli-kwə-ˌdāt\
Function: verb 
Inflected Form(s): liq·ui·dat·ed; liq·ui·dat·ing 
Etymology: Late Latin liquidatus, past participle of liquidare to melt, from Latin liquidus 
Date: circa 1575 
transitive verb
1 a (1) : to determine by agreement or by litigation the precise amount of (indebtedness, damages, or accounts) (2) : to determine the liabilities and apportion assets toward discharging the indebtedness of b : to settle (a debt) by payment or other settlement 
2 archaic : to make clear 
3 : to do away with 
4 : to convert (assets) into cash 
intransitive verb
1 : to liquidate debts, damages, or accounts 
2 : to determine liabilities and apportion assets toward discharging indebtedness}

Dissidents were all liquidated or driven into exile.

Where does this connotation of the verb 'liquidate' come from?