join up

verb (used with object)

1. to bring in contact, connect, or bring or put together: to join hands; to join pages with a staple.
2. to come into contact or union with: The brook joins the river.
3. to bring together in a particular relation or for a specific purpose, action, etc.; unite: to join forces against the smugglers.
4. to become a member of (an organization, party, etc.): to join a club.
5. to enlist in (one of the armed forces): to join the Navy.
6. to come into the company of; meet or accompany: I’ll join you later.
7. to participate with (someone) in some act or activity: My wife joins me in thanking you for the gift.
8. to unite in marriage.
9. to meet or engage in (battle, conflict, etc.): The opposing armies joined battle.
10. to adjoin; meet: His land joins mine.
11. to draw a curve or straight line between: to join two points on a graph.

verb (used without object)

12. to come into or be in contact or connection: a place where cliffs and sea join.
13. to become united, associated, or combined; associate or ally oneself; participate (usually followed by with): Please join with us in our campaign.
14. to take part with others (often followed by in): Let’s all join in.
15. to be contiguous or close; lie or come together; form a junction: Our farms join along the river.
16. to enlist in one of the armed forces (often followed by up): He joined up to fight for his country.
17. to meet in battle or conflict.

noun

18. a joining.
19. a place or line of joining; seam.
20. Mathematics. union(def 10a).

verb (adverb)

1. (intr) to become a member of a military or other organization; enlist
2. (often foll by with) to unite or connect

verb

1. to come or bring together; connect
2. to become a member of (a club, organization, etc)
3. (intr often foll by with) to become associated or allied
4. (intr usually foll by in) to take part
5. (tr) to meet (someone) as a companion
6. (tr) to become part of; take a place in or with
7. (tr) to unite (two people) in marriage
8. (tr) geometry to connect with a straight line or a curve
9. (tr) an informal word for adjoin
10. join battle to start fighting
11. join duty Indian to report for work after a period of leave or a strike
12. join hands
    1. to hold one’s own hands together
    2. (of two people) to hold each other’s hands
    3. (usually foll by with)to work together in an enterprise or task

noun

13. a joint; seam
14. the act of joining
15. maths another name for union (def. 9)

v.

c.1300, from stem of Old French joindre “join, connect, unite; have sexual intercourse with” (12c.), from Latin iungere “to join together, unite, yoke,” from PIE *yeug- “to join, unite” (see jugular). Related: Joined; joining. In Middle English, join sometimes is short for enjoin. Join up “enlist in the army” is from 1916. Phrase if you can’t beat them, join them is from 1953.