Generally accepted U.K. shorthand for Old Age Pensioner. This is over the age of 65 for men, and 60 for women. A move to raise the pension age to 67 has been mooted. This is possibly due to the storng aging demographic of the UK. In 20 years' time, it is estimated that the working population will no longer be able to support the non-working population. To counteract this, a raise in the pension age would add two or seven years to your compulsory working life, assuming that you are not in the privileged position of being able to take an early retirement.