One of requirements for CGT relief is to be working director for no. of years
My wife satisfies all other conditions, holds 40% shares in the company.
Her name is not on letterhead or Company Annual Accounts , but for her PAYE she is classified as a Proprietary Director
Section 598 TCA deals with retirement relief (not on disposal to family) and it does not define director. I would therefore take that to mean that a director as it is normally known (i.e. of the company and on the directors' register and CRO notification etc). There are various provisions which define director for specific chapters or parts but I don't think this is one of them. As T McGibney mentions you can should get advice on this as I've only taken a cursory glance as the retirement relief provision is very subtle/complex.
I had a case where the wife was a listed director for 20 years and the question arose whether she was in fact a full time working director on the basis that she did the admin for the business.