Saw emergency room cover ordinary streak of light (6)
I believe the answer is:
meteor
'streak of light' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'saw emergency room cover ordinary' is the wordplay.
'saw' becomes 'met' ('meet' can be a synonym of 'see').
'emergency room' becomes 'er' (abbreviation popularized by US TV series).
'cover' indicates putting letters inside.
'ordinary' becomes 'o' (abbreviation e.g. O-Levels).
'er' enclosing 'o' is 'eor'.
'met'+'eor'='METEOR'
Can you help me to learn more?
(Other definitions for meteor that I've seen before include "A space-traveller" , "Glowing body entering atmosphere" , "Small extraterrestrial body" , "rock falling to earth" , "streaker?" .)