Meaning of DE- in English

de- /diː, dɪ/ BrE AmE prefix

[ Language: Old French ; Origin: Latin de- 'from, down, away' and Latin dis- 'apart' ]

1 . shows an opposite:

deindustrialization (=becoming less industrial)

2 . shows that something is removed:

Debone the fish (=remove its bones) .

The king was dethroned (=removed from power) .

3 . shows that something is reduced:

The government have devalued the currency.

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.