H21

H21 or H 21 stands for:

• the code name of the spy Mata Hari in the German secret service
• Junkers H 21 , German multi-purpose aircraft
• HMS H21 , British submarine
• a subgroup of haplogroup H in human genetics
• the Cyrillic spelling of the N 21 highway (Ukraine)

H-21 stands for:

• Piasecki H-21 , American transport helicopter

This is a disambiguation page for differentiating between several terms identified with the same word.