Meanings

battle formation

outer sanctum

fighting with one's back to the wall

phalanx

Latin square

magic square (matrix)

Braxton-Hicks contractions

labor-inducing drugs

one's own ground

bell or gong used to signal soldiers

each encampment

labor room

opposing side

engineering staff

hypotonic contractions (during labor (labour))

press corps

disposition of troops

field ration (Sengoku period)

summoning circle (esp. in fantasy fiction)

single line (of ships)