one-way

Short definition from Wiktionary

Adjective

1. 1
   Allowing movement, vision, etc. in only one direction; unidirectional.
2. 2
   Allowing travel in only one direction.
3. 3
   Of a function: easy to compute for every input, but hard to invert given the image of a random input.
4. 4
   Alternative form of one-way.

Verb

1. 1
   To use a disc harrow to turn the soil and kill weeds, in preparation for planting seeds.