1
general::
Phrase(s): put on weight
to gain weight; to get fat. • I think I am putting on a little weight. I had better go on a diet. • He has put on a lot of weight since last year.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
see PUT ON, def. 5. put our heads together Also, put their heads together. Discuss or plan something among ourselves (or themselves), as in Let's put our heads together and figure out what we can give him for his birthday. This idiom, alluding to combining mental forces, originated in the late 1300s as lay our heads together and acquired its current form in the second half of the 1800s.
American Heritage Idioms