field work

noun

1. Also field work. work done in the field, as research, exploration, surveying, or interviewing: archaeological fieldwork.
2. Fortification. a temporary fortification constructed in the field.

noun

1. an investigation or search for material, data, etc, made in the field as opposed to the classroom, laboratory, or official headquarters

noun

1. military a temporary structure used in defending or fortifying a place or position