Verb (5-dan, る, intransitive)
1.  to be added to;  to be appended
2.  to join in (e.g. a group of friends);  to participate
3.  to increase (e.g. heat);  to gain in (e.g. influence);  to grow;  to gather (speed)
4.  to be applied (e.g. heat, pressure);  to be exerted