get it up v.(orig. US)
1. [1930s+] (also get one up, get up) to achieve an erection; occas. in fig. use of a woman; .
2. [mid-19C] of a woman, to stimulate the penis to erection.
3. [1950s] (US Und.) to amass and produce a required sum of money, e.g. in payment of an outstanding debt.
4. [1970s+] in fig. use, to maintain enthusiasm for an idea, situation etc.