The term 'penned up' is often used to describe a feeling of being confined or restricted. This can be seen in the four crossword solutions for the term, which are STIED (5 letters), COOPED (6 letters), CAGED (5 letters), and IMPED (5 letters). Each of these words implies a sense of being held back or limited in some way. Stied, for example, means to tie or bind something, while COOPED suggests being kept in a small space, such as a coop. CAGED implies being held in an enclosure, and impeded suggests being hindered or blocked from progressing. All of these words together paint a picture of someone who is unable to move freely due to external forces.