first lieutenant

1. The second lowest rank of a commissioned officer in the United States Army, Air Force, or Marine Corps, ranking above a second lieutenant and below a captain. The rank of first lieutenant is equivalent to the naval rank of lieutenant junior grade.

   Leutnant, Oberleutnant

   пе́рвый лейтена́нтpérvyj lejtenánt, ста́рший лейтена́нтstáršij lejtenánt

   a commissioned officer in the Army or Air Force or Marines ranking above a 2nd lieutenant and below a captain

2. An equivalent rank in other military forces.

regular