The term 'WELLED (UP)' is a verb that means to fill with liquid or to swell. It is often used in the context of tears, which is why it is related to the crossword solution 'TEARED (6 letters)'. The two terms are similar in that they both refer to an action involving liquid, but 'WELLED (UP)' implies a gradual filling or swelling, while 'TEARED (6 letters)' implies a sudden release of liquid.