We found 3 dictionaries that define the word space helmets:

General (2 matching dictionaries)

1. space helmets: Collins English Dictionary
2. space helmets: Vocabulary.com

Slang (1 matching dictionary)

3. Space helmets: Urban Dictionary

(Note: See space_helmet as well.)

Definitions from Wiktionary (space helmet) ▸ noun:  A helmet worn by astronauts to protect from the vacuum of outer space. ▸ Also see space_helmet ▸ Words similar to space helmets ▸ Usage examples for space helmets ▸ Idioms related to space helmets ▸ Wikipedia articles (New!) ▸ Words that often appear near space helmets ▸ Rhymes of space helmets ▸ Invented words related to space helmets