particle
double-
B1
'doppel-' is a German prefix meaning 'double-' or 'twofold'. It forms compounds (e.g. Doppelzimmer) and intensifies quantity or pairhood. It is bound, written with hyphen in dictionaries and not used alone. No case or conjugation; behaves as part of the compound word.
Examples
Die Redaktion erklärte, dass das Präfix doppel- in einigen Titeln benutzt wurde, obwohl viele Leser es verwirrend fanden.
The editorial office explained that the prefix doppel- was used in some headlines, although many readers found it confusing.
Das Präfix 'doppel-' zeigt an, dass etwas zweimal oder paarweise vorhanden ist.
The prefix 'doppel-' shows that something is present twice or in pairs.
Details
Mnemonics
Imagine two identical items stuck together with a hyphen between them: doppel- means 'two of the same'.
Looks and sounds like English 'double-'.
Notes
The entry represents the prefix 'doppel-' used to form compound nouns/adjectives (e.g., Doppelzimmer, Doppelgänger). It is not a standalone word but a productive prefix.