a paper aeroplane

stationing in Japan

parking of a bicycle

to park a bicycle

necessary evil

necessity (quality or state of being necessary, unavoidable, or absolutely requisite)

unnecessary

needlessness

a machine, a device; a contraption / a loom / an opportunity, a chance to do something; the right time or moment / something of great importance: the linchpin of the matter

indicates aircraft / indicates paper aeroplanes / indicates lives in video games