E

• east or eastern longitude

  ICAO

• Eastern Standard Time (time groups only)

  Weather

• ending of precipitation (time in minutes) (weather reports only)

  Weather

• equatorial (air mass)

  Weather

E has 4 meanings; the right one depends on context. A weather report, a NOTAM or an ATC clearance. Got a NOTAM full of contractions? Paste it into the decoder.

Source: FAA Order JO 7340.2 Contractions. Not for operational use.