Change the wording of any bit of text or string, which has a context

change-wording-with-context.php

<?php

function tribe_custom_theme_text_with_context ( $translation, $text, $context, $domain ) {
 
	// Put your custom text here in a key => value pair
	// Example: 'Text you want to change' => 'This is what it will be changed to'
	// The text you want to change is the key, and it is case-sensitive
	// The text you want to change it to is the value
	// You can freely add or remove key => values, but make sure to separate them with a comma
	// This example changes the label "Venue" to "Location", and "Related Events" to "Similar Events"
	$custom_text = array(
		'RSVP' => 'Registration',
	);
	
	// If this text domain starts with "tribe-", "the-events-", or "event-" and we have replacement text
    	if( (strpos($domain, 'tribe-') === 0 || strpos($domain, 'the-events-') === 0 || strpos($domain, 'event-') === 0) && array_key_exists($translation, $custom_text) ) {
		$translation = $custom_text[$translation];
	}
    return $translation;
}
add_filter('gettext_with_context', 'tribe_custom_theme_text_with_context', 21, 4);