stale

Example:The marketing team was accused of coming up with old-hat ideas for the campaign.

Definition:an idea or way of doing things that is no longer considered innovative or exciting

Example:Technology has moved so quickly that many of the systems we use are now outdated.

Definition:not current or up-to-date; no longer suitable or relevant

Example:The tired old approach to problem-solving was not helping to resolve the conflict.

Definition:lacking freshness or interest; no longer effective or attractive

Example:His long-in-the-tooth thoughts about the future were not helping the situation improve.

Definition:used to describe something that is old-fashioned or no longer suitable